补齐画板视频封面持久化

生成画板视频时截取首帧并上传为封面

将视频生成结果写入素材库并保留 thumbnailSrc

同步后端契约、SpacetimeDB 绑定、前端素材库和画布层映射

补充相关测试与文档说明

src/services/image-editor/editorProjectClient.ts

@@ -97,6 +97,7 @@ export type EditorAssetSnapshot = {
   folderId: string;
   label: string;
   imageSrc: string;
+  thumbnailSrc?: string | null;
   objectKey?: string | null;
   assetObjectId?: string | null;
   width: number;
@@ -329,10 +330,13 @@ export type EditorVideoGenerationInput = {
   generationInputs?: EditorAssetGenerationInputs | null;
   sourceResourceId?: string | null;
   assetKind?: string | null;
+  assetFolderId?: string | null;
+  assetLabel?: string | null;
 };
 
 export type EditorVideoGenerationResult = {
   videoSrc: string;
+  thumbnailSrc?: string | null;
   objectKey?: string | null;
   assetObjectId?: string | null;
   width: number;
@@ -343,8 +347,10 @@ export type EditorVideoGenerationResult = {
   model: string;
   provider: string;
   taskId: string;
+  durationSeconds: number;
   priceMudPoints?: number;
   project?: EditorProjectSnapshot | null;
+  asset?: EditorAssetSnapshot | null;
   queueState?: ExternalGenerationJobStatusRecord | null;
 };
 
@@ -912,6 +918,8 @@ export async function generateEditorVideo(input: EditorVideoGenerationInput) {
         ? { sourceResourceId: input.sourceResourceId }
         : {}),
       ...(input.assetKind ? { assetKind: input.assetKind } : {}),
+      ...(input.assetFolderId ? { assetFolderId: input.assetFolderId } : {}),
+      ...(input.assetLabel ? { assetLabel: input.assetLabel } : {}),
     }),
     '生成视频失败',
     {